Third game!
You have a giant aquarium. You start out with only one pokemon, which is poliwag. You have to feed it, play with it, and evolve it. When it evolves, its evolved form will become unlocked. When a pokemon is unlocked, you can have five of that pokemon in the aquarium. Poliwag will have to be evolved three times ( poliwag to poliwhirl to poliwrath to politoad) to unlock another breed of pokemon. This is a list that shows the order pokemon breeds will be unlocked
1.poliwag to poliwhirl to poliwrath to politoad
2.goldeen to seaking
3.horsea to seadra to kingdra
4.shellder to coyster
5.dratini to dragonair(no dragonite)
6.feebas to milotic
7. Magikarp to gyrados
8.remoraid to octillery
9.mantyke to mantine
10.Chinchou to Lanturn
11. clampearl to huntail to gorebyss
12. spheal to sealo to walrein
13.seel to dewgong
14.kyogre
there is also a special event pokemon if you breed milotic and dragonair(milotair) I'm thinking of a dragonair body (blue and white) with white long earflaps. look at this for inspiration:
esepibe.deviantart.com/art/Fusion-Dragonair-Milotic-65807871
As i said you can breed. You can make more cross breeds if you'd like.

PLEASE post! Please post the name of the game and tell if you like the ideas